package com.my.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Date;
import java.util.HashMap;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class CheckCode {

	private Random random = new Random();
	private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";// 随机产生的字符串

	private int width = 80;// 图片宽
	private int height = 30;// 图片高
	private int lineSize = 40;// 干扰线数量
	private int stringNum = 4;// 随机产生字符数量
	/*
	 * 获得字体
	 */

	private Font getFont() {
		return new Font("Fixedsys", Font.CENTER_BASELINE, 20);
	}

	/*
	 * 获得颜色
	 */
	private Color getRandColor(int fc, int bc) {
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int r = fc + random.nextInt(bc - fc - 16);
		int g = fc + random.nextInt(bc - fc - 14);
		int b = fc + random.nextInt(bc - fc - 18);
		return new Color(r, g, b);
	}

	/**
	 * 
	 * @param overtime  验证码有效时长，单位分钟
	 * @param request
	 * @param response
	 */
	public void getRandcode(int overtime,HttpServletRequest request, HttpServletResponse response) {
		HttpSession session = request.getSession();
		// BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
		// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
		Graphics g = image.getGraphics();
		g.fillRect(0, 0, width, height);
		g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 20));
		g.setColor(getRandColor(110, 133));
		// 绘制干扰线
		for (int i = 0; i <= lineSize; i++) {
			drowLine(g);
		}
		// 绘制随机字符
		String randomString = "";
		for (int i = 1; i <= stringNum; i++) {
			randomString = drowString(g, randomString, i);
		}
		Date date = new Date();
		session.removeAttribute("checkcode");
		session.removeAttribute("yztime");
		session.setAttribute("checkcode", randomString);
		session.setAttribute("yztime", new Date(date.getTime()+overtime*60*1000));
		g.dispose();
		try {
			ImageIO.write(image, "JPEG", response.getOutputStream());// 将内存中的图片通过流动形式输出到客户端
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/*
	 * 绘制字符串
	 */
	private String drowString(Graphics g, String randomString, int i) {
		g.setFont(getFont());
		g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121)));
		String rand = String.valueOf(getRandomString(random.nextInt(randString.length())));
		randomString += rand;
		g.translate(random.nextInt(3), random.nextInt(3));
		g.drawString(rand, 13 * i, 16);
		return randomString;
	}

	/*
	 * 绘制干扰线
	 */
	private void drowLine(Graphics g) {
		int x = random.nextInt(width);
		int y = random.nextInt(height);
		int xl = random.nextInt(13);
		int yl = random.nextInt(15);
		g.drawLine(x, y, x + xl, y + yl);
	}

	/*
	 * 获取随机的字符
	 */
	public String getRandomString(int num) {
		return String.valueOf(randString.charAt(num));
	}
	
	/**
	 * 
	 * @param CheckCode   用户输入的验证码
	 * @param session
	 * @return
	 */
	public HashMap<String, Object> vertfyCode(String CheckCode, HttpSession session) {

		HashMap<String, Object> map = new HashMap<String, Object>();
		try {
			String sessionCode = (String) session.getAttribute("checkcode");
			Date yztime = (Date) session.getAttribute("yztime");
			Date now = new Date();
			String code = CheckCode.toUpperCase();
			if(now.getTime() < yztime.getTime()){
				if (sessionCode.equals(code)) {
					map.put("success", true);
					map.put("msg", "验证码正确");
				} else {
					map.put("success", false);
					map.put("msg", "验证码错误，重新输入");
				}
			}else{
				map.put("success", false);
				map.put("msg", "验证码过期，请刷新");
			}
		} catch (Exception e) {
			e.printStackTrace();
			map.put("success", false);
			map.put("msg", e.getMessage());
		}
		return map;
	}
}
